Epicardial Coronary Spasm Mimicking Right Coronary Artery Occlusion in a Transplant Recipient Presenting With Syncope

BACKGROUND: Epicardial coronary vasospasm is an underrecognized complication in heart transplant recipients and may present atypically due to cardiac denervation. CASE SUMMARY: A 55-year-old male, heart transplant recipient presented to an outside hospital with unexplained syncope. Electrocardiogram showed sinus rhythm with a known right bundle branch block. Workup revealed stable high-sensitivity troponin, and telemetry showed no arrhythmias. Echocardiogram demonstrated preserved biventricular function. Neurologic evaluation was unrevealing. Due to persistent concern for allograft pathology or ischemia, the patient underwent left and right heart catheterization. Hemodynamics were normal. The left coronary system was angiographically normal. The right coronary artery appeared completely occluded proximally; however, intracoronary nitroglycerin administration resulted in full resolution, consistent with severe epicardial vasospasm. DISCUSSION: This case illustrates a rare but important presentation of reversible epicardial coronary spasm in a transplanted heart, manifesting as syncope without electrocardiogram changes. It underscores the need to consider vasospasm in transplant patients with atypical symptoms. TAKE-HOME MESSAGE: In transplant recipients, epicardial coronary vasospasm may present without chest pain. Coronary spasm should be considered in the differential for unexplained syncope in this population.